This paper describes a visible-light-driven photoredox catalytic strategy for the facile preparation of N,N-disubstituted-2-imidazolidinones from Weinreb-type amides (WAs) and N-acyl enamines. The reaction commences with the photoredox-catalyzed heterolysis of the N-O bond in the WAs, generating a nitrogen-centered amidyl radical. This radical subsequently adds to the enamine with high regioselectivity, triggering a tandem process comprising a radical Smiles rearrangement and an intramolecular acyl-retentive cyclization. This cascade ultimately leads to the formation of a highly reconstructed 2-imidazolidinone scaffold. This study presents a novel, straightforward approach to the synthesis of diversely substituted 2-imidazolidinones.
Feng et al. (Mon,) studied this question.